Improved motor performance in patients with acute stroke using the optimal individual attentional strategy

Abstract

It is believed that motor performance improves when individuals direct attention to movement outcome (external focus, EF) rather than to body movement itself (internal focus, IF). However, our previous study found that an optimal individual attentional strategy depended on motor imagery ability. We explored whether the individual motor imagery ability in stroke patients also affected the optimal attentional strategy for motor control. Individual motor imagery ability was determined as either kinesthetic-or visual-dominant by a questionnaire in 28 patients and 28 healthy-controls. Participants then performed a visuomotor task that required tracing a trajectory under three attentional conditions: no instruction (NI), attention to hand movement (IF), or attention to cursor movement (EF). Movement error in the stroke group strongly depended on individual modality dominance of motor imagery. Patients with kinesthetic dominance showed higher motor accuracy under the IF condition but with concomitantly lower velocity. Alternatively, patients with visual dominance showed improvements in both speed and accuracy under the EF condition. These results suggest that the optimal attentional strategy for improving motor accuracy in stroke rehabilitation differs according to the individual dominance of motor imagery. Our findings may contribute to the development of tailor-made pre-assessment and rehabilitation programs optimized for individual cognitive abilities.Cognitive factors such as attention direction 1,2 and motor imagery ability 3,4 can affect motor performance. Directional attention can follow two strategies when performing physical activity: internal focus (IF) and external focus (EF) 5 . In the IF strategy, attention is directed to body movement itself, whereas in the EF strategy, attention is directed to movement outcome. Previous studies have demonstrated the advantages of the EF strategy for motor performance in healthy populations 1,2 . The advantage of the EF strategy is explained by the constrained-action hypothesis; attempts to consciously monitor/control body movements (IF strategy) interfere with automatic motor control processes. However, the interference can be weakened by applying the EF strategy 6 . This hypothesis is also supported by empirical findings based on movement correction frequency 6 , attentional-capacity demands 7 , and electromyography during motor learning tasks 8 .Like the attentional strategy, motor imagery can be categorized into two distinct modalities, kinesthetic and visual motor imageries 9 . Kinesthetic motor imagery requires simulating the feeling of muscle or joint sensations, while visual motor imagery involves mentally visualizing one's body movements. These distinct motor imagery abilities vary across individuals, and the individual differences affect the acquisition of new movements 10 .Although both attentional strategy and individual motor imagery ability can affect motor performance, the specific effects of IF and EF strategies 11,12 and of individual abilities for kinest...

Individual optimal attentional strategy during implicit motor learning boosts frontoparietal neural processing efficiency: A functional near‐infrared spectroscopy study

“…Figure 3c shows the differential modality scores on the MIQ-R (∆MI). This significant correlation between individual cognitive ability and motor performance is consistent with our previous reports examining healthy (Sakurada et al, 2016) and stroke populations (Sakurada et al, 2017). Furthermore, we found a significant positive correlation between ∆MI and ∆AE (Figure 3d, r = 0.52, p = 0.005).…”

“…Furthermore, we found a significant positive correlation between ∆MI and ∆AE (Figure 3d, r = 0.52, p = 0.005). This significant correlation between individual cognitive ability and motor performance is consistent with our previous reports examining healthy (Sakurada et al, 2016) and stroke populations (Sakurada et al, 2017). The t values of time averages are superimposed onto a brain surface.…”

“…The lack of an EF strategy advantage was also reported in a leg stepping task for patients with stroke (Kal et al, 2015). Furthermore, our recent studies demonstrated that the EF strategy did not always lead to better motor performance in healthy and stroke populations (Sakurada, Hirai, & Watanabe, 2016;Sakurada, Nakajima, Morita, Hirai, & Watanabe, 2017). We hypothesized that individual optimal attentional strategy varies depending on the ability for motor imagery, and so we assessed the modality dominance of motor imagery using questionnaires.…”

“…For instance, low-skill golfers showed better performance under IF instructions than under EF instructions (Perkins-Ceccato et al, 2003). Furthermore, our recent studies demonstrated that the EF strategy did not always lead to better motor performance in healthy and stroke populations (Sakurada, Hirai, & Watanabe, 2016;Sakurada, Nakajima, Morita, Hirai, & Watanabe, 2017). Furthermore, our recent studies demonstrated that the EF strategy did not always lead to better motor performance in healthy and stroke populations (Sakurada, Hirai, & Watanabe, 2016;Sakurada, Nakajima, Morita, Hirai, & Watanabe, 2017).…”

“…It has been proposed that the dorsolateral prefrontal cortex maintains behavioral goals in working memory and protects them from distracting information, and the inferior parietal lobe initiates shifts of attention and maintains attention on the relevant stimulus (Ptak, 2012). Furthermore, the frontal cortex has an important role in processing internal body information such as tactile stimuli (Pleger et al, 2006) and haptic information (Kaas, Mier, & Goebel, 2007), and we recently reported that the individual capacity to process internal body information can determine the optimal attentional strategy (Sakurada et al, 2017). These findings imply that frontal cortex is a potential region where individual differences in neural activity may contribute to optimal attentional strategy during motor tasks.…”